choroplethr: Simplify the Creation of Choropleth Maps in R

Choropleths are thematic maps where geographic regions, such as
states, are colored according to some metric, such as the number of people
who live in that state. choroplethr simplifies this process by 1.
Providing ready-made functions for creating choropleths of common maps. 2.
Providing API connections to interesting data sources for making
choropleths. 3. Providing a framework for creating choropleths from
arbitrary shapefiles. Please see the vignettes for more details.